Mower- conditioner header speed control based on forward travel speed

ABSTRACT

A self-propelled mower-conditioner includes a rotary cutter bar that feeds cut crop to a driven crop conveying arrangement which delivers the crop to a windrow forming arrangement. The speed at which the crop conveying arrangement delivers crop to the windrow forming arrangement is controlled so as to be a predetermined ratio of the ground speed.

FIELD OF THE INVENTION

The present invention relates to self-propelled mower conditioners andmore specifically relates to controlling the speed of crop flow throughthe machine.

BACKGROUND OF THE INVENTION

Mower-conditioners typically operate within a ground speed range from 5to 10 mph when mowing. When the vehicle is operated at this speed, cropflows into the header at this rate, is temporarily accumulated, and thenexpelled out the rear of the mower-conditioner to form a windrow. Theuniformity of the formed windrow density (defined as quantity of cropper unit area) is constant as long as the forward travel speed of themower-conditioner is unchanged. However, when the forward speed isreduced significantly, much of the crop that has been accumulated in theheader at the higher speed is expelled from the rear of themower-conditioner at this significantly reduced speed resulting in abunching up of the crop with an attendant increase in the windrowdensity. The bunched up crop dries slower than the crop in the remainingportions of the windrow that is formed at a lesser crop density causinga delay in the time that the crop can be baled without resulting inspoilage. It is noted that bunched up crop occurs most of the time atthe headlands of the field when the operator slows down to turn themower-conditioner around for the next pass through the field.

Accordingly, what is needed is some way to prevent crop from bunching upduring a significant reduction in the ground speed of themower-conditioner, as when turning at the headland of a field duringmowing operation.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a novelmower-conditioner control system for overcoming the aforementionedproblem of introducing bunched crop into a windrow being formed.

An object of the invention is to control the speed of the delivery ofcut crop for the formation of a windrow so that crop bunching is reducedor eliminated.

The aforementioned object is achieved by controlling the delivery speedof the internal components of the mower-conditioner in proportion toforward travel speed. This is achieved in a hydraulically driven

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, left front perspective view of a self-propelledmower-conditioner of the type with which the present invention isparticularly adapted for use.

FIG. 2 is a schematic of an electro-hydraulic control system for theself-propelled mower-conditioner shown in FIG. 1 and having the purposeof slowing the rate that cut crop is conveyed through the windrower whenoperating at travel speeds below that normally occurring at typicalmowing speeds.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is shown a self-propelled mower-conditioner10 operable to mow and collect standing crop in a field, condition thecut crop as it moves through the machine to improve its dryingcharacteristics, and then return the conditioner material to the fieldin a windrow or swath. The windrower 10 includes a main frame 12supported on driven right and left front wheels 14R and 14L,respectively and on right and left caster mounted rear wheels, of whichonly a left rear wheel 16L is shown. Carried on a forward end region ofthe frame 12 is a cab 18. Mounted on the frame 12 behind the cab 18 is ahousing 20 within which is located a power source (not shown) such as aninternal combustion engine. A harvesting header 22 is coupled, in a wellknown manner, so as to be supported by the forward end of the frame 12.Operator controls (not shown) are provided in the cab 18 for operationof the mower-conditioner 10, including the attached harvesting header22.

The harvesting header 22 could take many configurations but is hereshown as including a rotary disc cutter bar 24 that delivers cut crop tofollowing crop converging auger 26 that delivers crop rearward into adischarge passage 28 for further processing by a crop conditioningarrangement comprising upper and lower crop conditioner rolls 30 and 32,respectively. Conditioned crop is expelled to the rear the conditionerrolls 30 and 32 and is formed into a windrow by upright right and left,windrow forming panels (not shown) which are supported by a top wall ofan open-bottomed housing 34 located between the front wheels 14R and14L.

The rotary disc cutter bar 24 includes an elongate gear housing 36supporting a plurality of cutter discs 38 for rotation, with gearing(not shown) located within the housing 36 being arranged in a mannerwell known in the art so that the cutter discs 38 located rightward alongitudinal center line X are driven counterclockwise by a hydraulicfluid motor 40R coupled to the rightmost cutter disc 38, while thecutter discs 38 located leftward of the center line X are drivenclockwise by a hydraulic fluid motor 40L coupled to the leftmost cutterdisc 38.

Referring now to FIG. 2, there is shown an electro-hydraulic controlsystem 50 for controlling the operation of the front drive wheels 14Rand 14L, the rotary disc cutter bar 24, the converging auger 26 and theupper and lower crop conditioning rolls 32 and 34.

Specifically, the control system 50 includes right and left wheel drivemotors 52R and 52L, respectively coupled for driving the right and leftfront drive wheels 14R and 14L. Reversible, variable displacement fluidpumps 56 and 58 are respectively hydraulically coupled to the fluidmotors 52R and 52L by respective pairs of fluid hoses, or the like, andinclude respective displacement control levers 60 and 62 mounted forbeing pivoted fore-and-aft from respective neutral positions so as tochange the displacements of the pumps 56 and 58 so as to change thespeed and/or driving direction of the motors 52R and 52L. Control of thedisplacement control levers 60 and 62 is effected by manual operation ofa hydro-lever 64 that is mounted for being pivoted fore-and-aft within aguide slot (not shown) for effecting forward, neutral and reversedriving conditions in the front drive wheels, with speed increasing inthe forward direction with increasing pivotal movement of the lever in aforward direction F beyond a neutral position N, and with speedincreasing in the rearward direction with increasing pivotal movement ofthe lever in a rearward direction R beyond the neutral position N, as iswell known in the art. A lever position sensor 66 is associated with thehydro-lever 64 and generates an electrical speed and direction inputsignal corresponding to the angular position of the hydro-lever, and mayinclude information such as whether or not the hydro-lever is presentlymoving, the direction of movement, and the instantaneous speed ofhydro-lever movement. The signal generated by the sensor 66 is coupled,by a hydro-lever position signal lead 68, to an electronic control unit(ECU) 70. The ECU 70 processes the hydro-lever position signal and sendsout a desired proportional speed/direction control signal to an electriclinear actuator 72 by way of a speed/direction control signal line 74.The actuator 72 includes an output rod 76 coupled to an output link 78of a four-bar linkage 80, the output link 78 being mounted at one endfor pivoting about a fixed pivot 82 and having another end pivotallymounted to a control plate 84, as at 86. The control plate 84 isrespectively connected to the pump displacement control arms 60 and 62by motion transfer links 88 and 90. A position feedback sensor 92 isassociated with the actuator 72 and generates a feedback signal coupledto the ECU 70 by a feedback signal lead 94, with the feedback signalbeing processed by the ECU which operates to de-energize the actuator 70when it has moved a distance corresponding to the proportionalspeed/direction control signal which initially received by the actuator70. Also providing vehicle speed information for use by the ECU 70 is atravel speed sensor 96, shown here as associated with the wheel drivemotor 52L, the travel speed sensor 96 generating a signal representingthe travel speed, with the travel speed signal being coupled to the ECU70 by a travel speed signal lead 98.

The cutter bar drive motors 40R and 40L are driven through the agency ofa variable speed pump 100 to which the motors are connected in parallel.The speed that the motors 40R and 40L is selected by the operator byoperation of any well known hydraulic, electrical or electro-hydraulicdisplacement control means (not shown) for controlling the displacementof the pump 100 based on the type and condition of crop being cut,noting that the cutter discs 38 cut by impact and are required to berotated at a predetermined minimum speed for effecting effective,efficient cutting of crop regardless of the travel speed of themower-conditioner 10.

The converging auger 26 and the upper and lower conditioner rolls 32 and34 are driven by a reversible hydraulic motor 102 coupled, as indicatedby a dashed line 104, to an input shaft 106 of a gear case 108 havingfirst and second output shafts 110 and 112, respectively, coupled, asindicated by dashed lines 114 and 116, to stub shafts 118 and 120 at theleft ends of the upper and lower conditioner rolls 32 and 34. Gearingwithin the gear case 106 effects counter-rotation of the output shafts110 and 112, and thus counter-rotation of the conditioner rolls 32 and34 so that crop fed from the converging auger 26 will be grabbed at thenip of the rolls 32 and 34 and expelled rearward to the windrow formingplates. A stub shaft 121 at the right end of the lower conditioner roll34 is coupled for transferring power to a stub shaft 122 at the rightend of the converging auger 26 by a sprocket and chain drive 124, notingthat the rotation of the lower conditioner roll 34 results in overshotrotation of the auger 26. A reversible, variable speed pump 126 has aclosed loop connection with the motor 102 and includes a swash plate 128coupled to a piston of a hydraulic displacement controller 130, thepiston being received in a cylinder having ports at the opposite side ofthe piston coupled to a solenoid-operated proportional direction controlvalve 132 for selectively receiving fluid from a charge pump 134 orreturning fluid to a sump 136. The control valve 132 includes a solenoid138 that is coupled for receiving a crop throughput speed control signalfrom the ECU by way of a throughput speed control line 140. A throughputspeed sensor 142 is associated with the converging auger 26 andgenerates a representative throughput speed signal that is sent to theECU 70 by way of a throughput speed signal line 144. The ECU 70 may beprogrammed to set a minimum throughput speed at which the convergingauger 26 and upper and lower conditioner rolls 32 and 34 must be drivenso that crop flows through the header 24 at a speed sufficient toprevent or minimize plugging. For example, if the ratio of throughputspeed to ground speed is 1-to-1, the minimum throughput speed may beequivalent to a forward ground speed of 2 mph.

A manual input device 146 is provided for selecting a desired groundspeed dependent ratio at which the throughput speed of the convergingauger 26 and conditioner rolls 32 and 34 will be caused to automaticallyoperate once a ground speed is selected by operation of the hydro-lever64. Depending on the crop and crop condition, the desired cropthroughput speed to ground speed ratio is selected by an input dial 148,the input device 146 generating an electrical ratio signal representingthe selected ratio, with this ratio signal being connected to the ECU 70by a ratio signal lead 150. A speed ratio feedback lead 152 is coupledbetween the ECU 70 and manual input device 146, which includes a display154 for displaying the speed ratio processed by the ECU by using theinformation gathered from the actuator position sensor 92 and/or groundspeed sensor 96, and throughput speed sensor 142.

It is here noted that it may be desirable to construct the speed ratioselecting device 146 so that it automatically increases the speed ratioa modest amount in response to the hydro-lever position sensor 66indicating that the hydro-lever 64 has been moved so as to decrease theoperating speed. This will insure that crop bunching does not occurduring slow down of the mower-conditioner 10 while harvesting crop.

The following describes an operation of the mower-conditioner 10 in amanner for ensuring that crop flow through the header 22 remainsrelatively uniform, especially when the operator reduces ground speed,as when at an end of a field, for example, so as to avoid or reducelarge clumps of crop from being introduced into the windrow being formedby windrow forming shields engaged by the crop expelled by theconditioner rolls 32 and 34. In preparing the mower-conditioner 10 foroperation in a field containing standing crop to be cut and windrowed,the operator will first set the displacement of the variabledisplacement pump 100 so as to cause the cutter bar motors 40R and 40Lto be driven at a speed resulting in the discs 38 being rotated at adesired speed for efficiently and effectively cutting the crop, takinginto account the type of crop and its condition. Further, assuming thatthe crop condition is such that the mower-conditioner 10 can be operatedat a typical mowing speed, for example in the range of from 5 to 10 mph,the operator will use the dial 148 of the ratio selecting device 146 toselect a desired throughput speed to ground speed ratio. For example, atypical setting of the dial 148 may be that for effecting a 1-to-1 ratiofor average crop yields, this ratio being that obtained by placing thedial 48 in a straight up position, as illustrated, with each settingincrement counterclockwise from the straight up position reducing theratio by 0.2, for example, and each setting increment clockwise from thestraight up position increasing the ratio by 0.2, for example, withdecreasing ratios being more suitable for light crops and increasingratios more suitable for heavy crops.

The operator will then use the hydro-lever 64 to increase the forwardspeed of the mower-conditioner to the desired operating speed by pushingthe hydro-lever forward from its neutral position N. As the hydro-lever64 is pushed forwardly, the position sensor 66 will generate acorresponding position signal and transmit it to the ECU by way of thelead 68, with the ECU processing this input signal and outputting acontrol signal to the electric linear actuator 72 by way of the signallead 74. This energizes the linear actuator 76 so that it causes thecontrol rod 76 to retract and pivot the control lever 78 forwardly, asviewed in FIG. 2, and cause forward movement of each of the motiontransfer links 88 and 90 so as to respectively pivot the displacementcontrol levers 60 and 62 forwardly to increase the displacements of thepumps 56 and 58 so as to cause the front wheel drive motors 52R and 52Lto drive the front wheels 14R and 14L at the commanded forward speed.The rod position sensor 92 will sense the position of the actuator rod76 and send a feedback signal representing this movement to the ECU 70,by way of the feedback signal lead 94, the ECU processing this feedbacksignal and acting to deactivate the electrical linear actuator 72 whenthe position of the rod 76 corresponds to the commanded speed. At thesame time, the travel speed sensor 96 will generate a correspondingtravel speed signal which is sent to the ECU 70 by way of the signalline 98, this travel speed signal being processed by the ECU and usedtogether with the ratio setting to generate a throughput speed controlsignal which is sent to the solenoid 138 of the proportional directioncontrol valve 132 by way of the control signal lead 140. The valve 132shifts to control the flow of fluid to the displacement controller 130so that the pump 126 pumps fluid for causing the motor 102 be driven forcausing the converging auger 26 and conditioner rolls 32 and 34 to bedriven to establish the pre-selected drive speed ratio. The convergingauger speed sensor 142 generates a speed signal corresponding to thespeed at which the converging auger 26 is rotated and transmits thisspeed signal to the ECU 70 by way of the lead 144. The ECU thenprocesses this signal, and when the speed of the converging auger 26reaches that wherein ratio of the peripheral speed of the auger 26 tothe ground speed corresponds to the ratio preselected by the ratiosetting device 146.

The windrower 10 will then travel across the field at the normaltraveling speed selected based upon the type and condition of the cropbeing harvested. Assuming that the windrower 10 is approaching the endof the field, the operator will effect a reduction in the speed bypulling back on the hydro-lever 64. The electrical linear actuator 74will again be energized, but this time the control rod 76 will beextended so as to cause the lever 78 to pivot rearward causing rearwardmovement of the motion transfer rods 88 and 90 and correspondingrearward movement of the displacement control levers 60 and 62 so as todecrease the displacements of the pumps 56 and 58 and correspondingdecreases in the speed of the front wheel drive motors 52R and 52L. Thecontrol rod position sensor 92 will sense the position of the rod 76 andgenerate a corresponding signal which is sent to the ECU 70 by way ofthe lead 94, the ECU 70 processing this signal and turning off thecontrol signal from the control lead 74 so as to de-energize theactuator 72 when the sensed position of the control rod 76 indicatesthat the control rod is in a new position corresponding to the travelspeed commanded by the rearward movement of the hydro-lever 64. At thesame time, the ECU 70 will have used the decreasing speed signalgenerated by the travel speed sensor 96 together with the preselectedratio to cause a decreasing control signal to be sent to the solenoid138 of the direction control valve 132 to cause it to shift and cause aproportional control of the position of the displacement controller 130of the pump 126 to effect a slowdown of the speed of operation of themotor 102, with the result that the speed of rotation of the convergingauger 26 will decrease, this decreasing speed being sensed by the sensor142 and sent for being processed by the ECU 70 so as to cause the signalto the solenoid 138 to be cut-off the de-energize the solenoid when theECU determines that the slowed converging auger 26 is operating at aspeed corresponding to that which results in the speed ratiopre-selected by the ratio selecting device 146 being obtained.

If the ratio selecting device 146 is constructed to automaticallyincrease the speed ratio a small amount when the hydro-lever positionsensing device 66 sends out a signal indicating that the travel speed isbeing diminished, then this new ratio will be that at which the ECU 70will terminate the signal to the control valve 132 converging auger whenthe ECU determines that the converging auger speed sensed by the sensor142 corresponds to that at which the peripheral speed of the convergingauger corresponds to that at which this increased speed ratio is met.

Having described the preferred embodiment, it will become apparent thatvarious modifications can be made without departing from the scope ofthe invention as defined in the accompanying claims.

The invention claimed is:
 1. In a mower conditioner having a framesupported for traveling over a field of crop at a variable ground speed,a header supporting a driven crop cutting arrangement across a forwardregion of the header, a windrow forming arrangement located at a rearregion of the header and a driven crop conveying arrangement located forreceiving cut crop from the cutting arrangement and delivering the cutcrop to the windrow forming arrangement, a crop conveying arrangementspeed control, comprising: a ground speed sensor providing an electricalground speed signal indicative of the forward ground speed of the mowerconditioner; an electronic controller coupled for receiving the groundspeed signal and being coupled for sending a control signal to thecontrollable drive device of the conveying arrangement; and saidelectronic controller being responsive to a decrease in ground speed forsending a control signal to the drive device of the conveyingarrangement for decreasing the speed of the drive device of theconveying arrangement by an amount proportional to a sensed decrease inground speed.
 2. The mower conditioner, as defined in claim 1, wherein apreset minimum crop conveying speed is programmed into the electroniccontroller; and said controller being responsive for preventing theconveying speed from being reduced below about two mph.
 3. A method forpreventing a bunching of crop in a formed windrow when reducing theground speed of a self-propelled windrower equipped with a cuttingarrangement for delivering cut crop to a crop conveying arrangement fordelivering the cut crop rearward to a windrow forming arrangement,comprising the steps of: a) pre-selecting a desired ground speed rangefor operation of the mower-conditioner; b) sensing the ground speed ofthe mower-conditioner; c) sensing the speed at which the crop conveyingarrangement is moving crop toward the windrow forming arrangement; andd) in response to the ground speed decreasing below the desired groundspeed range, reducing the speed at which the crop conditioning andconveying arrangement are driven by an amount related to the decrease inthe ground speed.
 4. The method for preventing bunching of crop, as setforth in claim 3, wherein the speed at which the crop conditioning andconveying arrangement is driven is a pre-selected fixed ratio of theground speed.
 5. The method for preventing bunching of crop, as setforth in claim 3, wherein the speed at which the crop conditioning andconveying arrangement is driven is never decreased below apre-established minimum speed value at which the crop conditioning andconveying arrangement must be driven to prevent plugging.
 6. The methodfor preventing bunching of crop, as set forth in claim 3, wherein thepre-selected minimum speed is approximately two mph.